Inheritance and allelic relationships of gene(s) for resistance to rice bacterial blight (Xanthomonas oryzae pv. oryzae) in some new donors.

摘要

Ten differential isogenic lines of rice (9 IRRB lines and IR8), 3 breeding lines (BG400-1, RP2151-33-2 and S.971) and 2 susceptible controls (MW10 and Madhuri) were screened for resistance to 6 isolates of X. oryzae pv. oryzae prevalent in the Chattisgarh region of Madhya Pradesh during kharif 1993. All 3 breeding lines were also crossed with MW10 and with each isogenic line exhibiting resistance to the same bacterial isolate as the breeding line. F1 and F2 plants were inoculated with the same specific isolate (109 cells/ml) at the tillering stage and screened for resistance during kharif 1994. A single recessive gene in RP2151-33-2 and BG400-1, and 2 complementary dominant genes in S.971 for resistance were detected. Allelic studies indicate thatgenes for resistance present in these breeding lines are different from the already reported resistance genes Xa-1, Xa-2, Xa-3, Xa-4, xa-5, Xa-7, xa-8, Xa-10, Xa-11 and Xa-1h..